安氏Ⅱ类错正畸治疗后稳定性探讨

Study of the Stability out of Retention in Angle Class Ⅱ Malocclusion by the PAR Index.

目的 :探讨影响安氏Ⅱ类错牙合矫治后稳定性的相关因素。方法 :采用PAR (peerassessmentrating )指数和牙弓测量方法对正畸治疗后 2～ 8年 30例安氏Ⅱ类错牙合患者模型测量评估。结果 :治疗后加权PAR分值减少 85 .91% ,保持后加权分值净减少 70 .30 %。极大改善治疗后为 80 % ,保持后为 6 3.33%。牙齿排列、覆盖、覆牙合、颊舌向颊牙合关系保持后PAR分值显著增加。上下 3- 3长度、牙弓长度、基骨长度及下 3- 3宽度减少。结论 :正畸治疗后 ,牙弓长度、下尖牙间宽度有缩小趋势 。

Objective:To investigate correlative factors affecting the stability out of retention after orthodontic treatment in Angle class Ⅱ malocclusion.Methods:The study models of thirty patients with Angle classⅡmalocclusion 2-8year out of retention were evaluated using the PAR (peer assessment rating) index and dental arch measurement.Results:The reduction was 85.91% after treatment, and was 70.30% out of retention in weighted PAR total scores. 80% were greatly improved after treatment and 63.33% were greatly improved out of retention.There was a significant increased between post-treatment and post-retention for alignment, overjet, overbite and transverse buccal occlusion in PAR scores. There was a significant decrease in intercanine length, dental arch length, and basal bone length in both jaws and lower intercanine width.Conclusions:There was a decreased trend in dental arch length and lower intercanine width, while intercanine and intermolar widths were more stable.